Dallas County twice tried to condemn killers but didn't send anyone to death row in 2017.

It hasn't for three years — and neither has Harris County.

Both were once leaders in a state known for putting convicted killers to death.

And although Texas remained the national leader in executions in 2017 — with seven — executions and new death sentences have been steadily declining over the past decade.

Nationwide, there were 39 death sentences issued in 2017, and 31 percent of those came from just three counties: Riverside County, Calif.; Clark County, Nev.; and Maricopa County, Ariz., according to a year-end study by the Death Penalty Information Center.

In Texas, only four people were sent to death row this year.

The four men sent to Texas' death row in 2017 (from left): William Hudson, who killed six people on a camping trip in Anderson County; John Falk, whose escape from a Huntsville-area prison led to the death of a correctional officer; Joseph Colone, who killed a Beaumont woman and her 16-year-old daughter; and Billy Tracy, who beat a prison guard to death at the Telford Unit.

And for the first time in more than 30 years, no one from Harris County was executed in 2017. Only one from Dallas was executed.

Nationally, only about half of Americans support the death penalty, a 45-year low, according to the year-end study.

Support is waning in Texas, too.

In 2017, the Texas Court of Criminal Appeals stayed six executions. Over three years, the court granted 21 stays, compared with just three between 2012 and 2014, according to the Texas Coalition Against the Death Penalty.

"The chorus of voices raising concerns about the death penalty is growing louder every day," said Kristin Houlé, executive director of the coalition. "Concerned citizens and elected officials should take a closer look at the realities of this irreversible, arbitrary, and costly punishment and pursue alternative means of achieving justice."

Meanwhile, the controversy over capital punishment is on the rise, whether because of botched executions, the exoneration of inmates who have spent decades on death row or the disproportionate number of minorities sentenced to death.

Legal reforms have also given prisoners more chances to have their sentences reviewed, and pursuing the death penalty can cost taxpayers millions.

Dallas County District Attorney Faith Johnson has said her office considers the severity of the crime, the desires of the victim's family and the criminal background of the accused before seeking the death penalty.

"Our office only seeks the death penalty in the most heinous and serious of crimes," Johnson said this year.

In 2018, Dallas and Harris counties will account for the first three executions — if they're carried out as planned.

William Rayford killed his ex-girlfriend while out on parole in the murder of his wife.

Two-time killer William Rayford, 64, is scheduled to die Jan. 30. He was convicted of the brutal 1999 killing of his ex-girlfriend, Carol Lynn Thomas Hall. The 44-year-old was stabbed, strangled and beaten before her body was discarded in a creek. At the time, Rayford was on parole after serving eight years of a 23-year sentence for killing his wife.

John Battaglia is scheduled for execution Feb. 1. The 62-year-old killed his daughters — Faith, 9, and Liberty, 6 — in 2001 at his Deep Ellum loft while on the phone with their mother.

"No, Daddy! Don't do it!" Faith pleaded, moments before her father pulled the trigger in an act of revenge against his ex-wife.

Battaglia was set to be executed in March 2016 but was granted a stay after seeking new legal counsel to help appeal the sentence. The Court of Criminal Appeals upheld his death sentence this year after he was found mentally competent.

John Battaglia is scheduled to die Feb. 1 for killing his daughters, 6-year-old Liberty (left) and 9-year-old Faith, in 2001.

About half of the death penalty cases tried in Texas since 2015 have resulted in a death sentence. In Dallas, prosecutors tried two death penalty cases in 2017, but jurors couldn't condemn the men.

A Dallas County jury deadlocked on whether Erbie Lee Bowser should be put to death for killing his girlfriend and her daughter at their Dallas home before driving to DeSoto, where he killed his estranged wife and her daughter.

Erbie Lee Bowser will spend his life in prison after a jury deadlocked on sentencing him to death.

(Dallas County Jail)

Four others were seriously injured in the attack. Bowser's defense argued the man didn't pose any continuing threat to society. He'll spend the rest of his life in prison.

The Dallas County district attorney's office has two pending death penalty cases, including the alleged gunman accused of killing dentist Kendra Hatcher in 2015 at an Uptown apartment parking garage. His trial is set for October.

Brenda Delgado, who's accused of hiring Kristopher Love to kill Hatcher, is not eligible for the death sentence because of an extradition agreement with Mexico.

Clockwise from top left: Kendra Hatcher was killed in a plot authorities say was orchestrated by her boyfriend's jealous ex-girlfriend, Brenda Delgado, and carried out by gunman Kristopher Love and getaway driver Crystal Cortes. Love faces trial in October.

The second case is a new punishment trial for a man who has been on death row for nearly a decade. The Texas Court of Criminal Appeals granted a reprieve for Hector Rolando Medina because of his defense attorney's "deficient performance."

Hector Rolando Medina won a reprieve and will get a new punishment trial in 2018.

(Dallas County Jail)

The Irving man was convicted of killing his baby girl and 3-year-old son in 2007. His attorney refused to call any witnesses to try to spare Medina's life during the punishment phase.

The district attorney had planned to seek the death penalty against a man accused of abducting 18-year-old Zoe Hastings from a Walgreens in Lake Highlands and then killing her in her minivan.

Antonio Cochran won't face the death penalty because he's been deemed intellectually disabled.

(Dallas County Jail)

In March, the U.S. Supreme Court ordered Texas to use modern medical standards to determine whether death row inmates are fit to be executed. The state had used medical standards from 1992.

Nationwide, four death row inmates were exonerated in 2017 because of flawed forensics, poor defense and prosecutorial misconduct, the national year-end report showed.

The report also showed that less than 1 percent of counties sentenced anyone to death, and 85 percent of counties have never executed anyone.

"Across the political spectrum, more people are coming to the view that there are better ways to keep us safe than executing a handful of offenders selected from a random death-penalty lottery," Robert Dunham, executive director of the Death Penalty Information Center, said in the nonprofit's year-end report.